I have a quick little note about something that very few outside of Redmond knew about and that is Xbox 360 Project "Helium". It was a concept to combine a high-end gaming Windows PC with a Xbox 360 motherboard as a daughterboard. It never was even remotely implemented and moved off the drawing boards but the idea was for a third party manufacturer to license and include a daughter board made by Microsoft that would be housed in a desktop PC to add an Xbox 360 functionality to the PC. Instead they went with Games For Windows LIVE.
The concept was not unlike a videogame PC hybrid like the Amstrad Mega PC and IBM Sega Teradrive PC that combined a 16-bit Sega Genesis/Megadrive with a PC or the Creative 3DO Blaster card that added 3DO functionality to a PC. Crazier ideas for game system hybrids have been made such as the MegaDrive Aiwa CSD-G1M combination Sega MegaDrive CD and portable boombox.